Motor vehicle suspension systems are configured so that the wheels are able to follow elevational changes in the road surface as the vehicle travels therealong. When a rise in the road surface is encountered, the suspension responds in “jounce” in which the wheel is able to move upwardly relative to the frame of the vehicle. On the other hand, when a dip in the road surface is encountered, the suspension responds in “rebound” in which the wheel is able to move downwardly relative to the integrated body or frame structure of the vehicle. In either jounce or rebound, a spring (i.e., coil, leaf, torsion, etc.) is incorporated with the body structure in order to provide a resilient response to the respective vertical movements of the wheel with regard to the vehicle body structure. However, in order to prevent wheel bouncing and excessive vehicle body motion, a shock absorber or strut is placed at the wheel to dampen wheel and body motion. An example of a MacPherson strut mount is disclosed in U.S. Pat. No. 5,467,971 to Hurtubise et al, issued on Nov. 21, 1995 and assigned to the assignee hereof.
It is known to provide hydraulic strut mounts, as for example disclosed in U.S. Pat. No. 7,347,437 to Oblizajek et al, issued on Mar. 25, 2008 and assigned to the assignee hereof. In this patent, a damper assembly for a suspension system of a motor vehicle includes a housing adapted to be mounted to one end of a strut of the suspension system. The housing has a chamber with fluid disposed therein. The damper assembly also includes at least one membrane extending transversely across the chamber so as to react with the fluid. The at least one membrane is composed of metal, being of a monolithic structure: integral, unitary and one piece.
What remains needed is a membrane having a high radial (transverse) stiffness and a relatively low axial stiffness, wherein such a membrane has adapatability for use in both hydraulic and conventional strut mounts, as well as other applications, and wherein the radial stiffness is directionally tunable for utilization in a particular application.